Data-logger Project help

Projects General Guidance
1

So I'm working on an industrial project.
I am a dentist, and an electronic hobbyist. I have a decent amount of information about electronics.

My project is a datalogger for an industrial environment, for that all circuits are placed in an industrial enclosure and an antenna will be sticking out of it. The creation is four logging bases. And a collection station. The collection station outputs the value to sdcard and serial port. And the clients will use an esp8266 to relay the values to the station. The station and client will have an arduino nano as the brain and the esp for communication only.. No other logic.. I am aware that the esp can handle the whole ordeal but in the first version..the nano will be used for ease.. Then the esp can take over in an upgrade.

I am really puzzled on how to design the system in terms of logic.
Values are collected every minute and esp cannot be left running to save power.. They only wake up when needed

  1. clients output basic http pages with the values needed and text parsing is used to obtain the values and write them down. Clients will wake up periodically to update the page and go back to sleep

  2. clients are sleeping and they get a wake up tcp signal.. Wake up .. Collect the values from sensors, spit them back over tcp.. Go back to sleep.

Don't know what to use.. TCP sockets or HTTP pages.. Wake up signal over WiFi or just a periodic update of values..

The only thing am decided on is the station sleeping for 45 seconds.. Waking up.. Possibly pinging everyone to wake, update and wait. And they are checked in order with confirmation containing a sleep command.. So they sleep until the next cycle.

this is a copy of a post I made in another forum. am posting it here to make you aware of my biggest problem. but the reason am posting here is, I need people to recommend me a way to manage the waking and sleeping of an arduino nano. the nano will have the sensors attached to it, and will send the values over serial, so I need it to wake up and do its thing and go back to sleep, what is the best method to implement this ? and if possible can you explain why ?
reliability is my number one objective here.

2

The arduino sleep library?

3

okay. i'll dig through that. meanwhile. i'll make the clients update values every 20 seconds automatically and send them over a serial connection to esp8266 which relays them over a TCP connection to the station.

every client has a 10 second time out. and i'll see if an IoT platform can be used to aggregate the data instead of an SD card. or an SD card in a comma delimited file.

if anyone has any suggestions, please pitch in. help is always welcome.

I'll post the code I put together for sleeping of esp and arduino. I'm sure someone else will find it useful

4

TCP is a protocol...not a hardware thing.

What do you mean by relay them via TCP? What is the point in having the wireless modules in the first place?

I personally think a network diagram may be useful here so we can make suggestions/improvements.

Size/range requirements, power requirements etc. will also be helpful. In all honest, some NRF chips and a slight knowledge on packet transmission (labelling, querying etc.) may be a more robust design.